This application is a competing renewal of P01 CA 33619 "Molecular Epidemiology of Nutrition and Cancer in the Multiethnic Cohort Study." The overall goal of the research is to conduct biomarker studies of cancer etiology, taking advantage of a recently established biorepository of blood, urine and buccal cells collected from more than 67,000 participants in this unique cohort. Specimens from substantial numbers of Japanese Americans, whites, African Americans, Latinos and Native Hawaiians have been stored in multiple aliquots at -186?C (blood) and -80?C (urine). A common theme of the research is the role of over-nutrition, obesity and/or chronic inflammation as underlying mechanisms for the effects of particular exposures on carcinogenesis. Four projects are proposed: 1) A study of nutritional and genetic risk factors for the main molecular subtypes of colorectal cancer;2) A study of interrelated metabolic pathways that may explain the ethnic and geographic variation in the risk of postmenopausal breast cancer;3) A study of the role of infection in prostate cancer risk;and 4) A study of inflammatory markers as mediators of nutritional exposures in the risk of non-Hodgkin lymphoma. These projects will be supported by three core components: 1) Administration;2) Biospecimens;and 3) Data Management and Analysis. We expect a total of nearly 5300 cases with stored prediagnostic blood and urine samples for the four cancer sites. Incident cancer cases will be identified through the population-based SEER tumor registries of Hawaii and California and matched to randomly selected controls. Data analyses will use nested case-control and case-case designs, and will apply data reduction techniques. The research will be highly integrated because of the many common scientific aims, the use of common resources, and the overlap in biomarkers and statistical methods. Provisions have been made to foster interactions among the investigators, so as to promote the scientific aims and enhance research accomplishments. Strengths of the program include the long-standing collaborations among the investigators;the extensive experience of the laboratory collaborators;the large number, unique ethnic diversity, and high quality of the biorepository specimens;and the population-based design of the Multiethnic Cohort. This P01 should add substantially to knowledge of cancer etiology, as well as to an understanding of the basis for ethnic/racial disparities in cancer occurrence.